If a specific single blue light is flashing (the left-most one when viewing from the outside and front of the car) it means the car is charging, and less than 1/3 full. If it's the middle- or right-most blue light flashing, while the one or two to its left are solid ON, then the car is also charging, and working on filling the 2nd or final 3rd of battery capacity.
If, however, a single flashing blue light slowly and continuously cycles thru the available three blue lights, it means the car is waiting for a timed-charge and has not yet started charging.
2011 Silver SL+QC [Mfg: 11/2010] 36mo/15k LEASE
06Jun2013 Status [28.5 months][34,173 miles][11 bars]
Lost CapacityBar 6/6/13 @34,173 miles while in LEAF Battery Monitor: 83.41%, 71.4F (avg); cool overnight;